Medical observation system, apparatus, control method, and imaging apparatus

ABSTRACT

A light emitting device irradiates a surgical area with first wavelength light and second wavelength light. A wobbling operation of a focus lens included in an imaging device is controlled according to an emission timing of the first wavelength light and the second wavelength light when the surgical area is alternately irradiated with the first wavelength light and the second wavelength light. The present disclosure can be applied to an endoscopic surgical system, for example.

TECHNICAL FIELD

The present disclosure relates to a medical observation system, acontrol apparatus, a control method, and an imaging apparatus, andparticularly, to a medical observation system, a control apparatus, acontrol method, and an imaging apparatus that enable more accurate AF tobe realized.

BACKGROUND ART

Generally, in medical observation apparatuses such as a surgicalendoscope and a surgical microscope, since the depth of field is shallowbut the surgical field is deep, so the region to be visually recognizedis not focused.

In contrast, medical observation apparatuses having an AF (Auto Focus)function that automatically focuses is proposed.

For example, PTL 1 discloses a medical observation system that obtains adeep-focus image with a low delay and a high frame rate by photographingwhile changing the focus position. Moreover, PTL 2 discloses a focuscontrol apparatus that performs focus control using wobbling.

CITATION LIST Patent Literature

-   PTL 1: JP 2017-6330A-   PTL 2: WO 2016/088187

SUMMARY OF INVENTION Technical Problem

In an imaging apparatus having the AF function, as disclosed in PTL 2,in order to determine a direction in which a focus lens is moved to anin-focus position, an operation called wobbling that slightly moves thefocus lens back and forth is often performed. With the wobblingoperation, an AF evaluation value for evaluating an in-focus state canbe obtained.

On the other hand, in a medical observation apparatus, a living tissueserving as a subject may be observed by alternately irradiating withnormal light and special light.

However, when normal light and special light are alternately irradiatedin the middle of a wobbling operation, there is a possibility that anappropriate AF evaluation value is not obtained. As a result, there is apossibility that highly accurate AF is not realized.

The present disclosure has been made in view of the above-describedproblems and enables more accurate AF to be realized.

Solution to Problem

A medical observation system according to a first aspect of the presentdisclosure is a medical observation system comprising: a non-transitorycomputer medium including computer program instructions, which whenexecuted by circuitry, cause the circuitry to control a light emittingdevice configured to irradiate a surgical area with first wavelengthlight and second wavelength light; control an imaging device configuredto capture an image of the surgical area; and control a wobblingoperation of a focus lens included in the imaging device according to anemission timing of the first wavelength light and the second wavelengthlight when the surgical area is alternately irradiated with the firstwavelength light and the second wavelength light.

An apparatus according to a first aspect of the present disclosure is anapparatus comprising: circuitry configured to obtain a plurality ofimages captured by an imaging device during a period of time duringwhich a first wavelength light and a second wavelength light arealternately irradiated; determine auto-focus evaluation values of atleast a first image and a second image each captured by receivingreflected light of the first wavelength light, wherein the first imageand the second image are captured with a focus lens of the imagingdevice in different positions; and determine a movement amount andmovement direction of the focus lens by comparing the auto-focusevaluation values of the at least the first image and the second image.

A medical observation method according to a first aspect of the presentdisclosure is a medical observation method performed by a medicalobservation system including a light emitting device that irradiates asurgical area with first wavelength light and second wavelength light,and circuitry configured to control an imaging device that captures animage of the surgical area, the method comprising: controlling awobbling operation of a focus lens included in the imaging deviceaccording to an emission timing of the first wavelength light and thesecond wavelength light when the surgical area is alternately irradiatedwith the first wavelength light and the second wavelength light.

An imaging apparatus according to a second aspect of the presentdisclosure is an imaging apparatus comprising: a light emitting devicethat irradiates a subject with first wavelength light and secondwavelength light; and circuitry configured to control an imaging devicethat captures an image of the subject, wherein in a wobbling operationof a focus lens included in the imaging device, the circuitry performscontrol to not move the focus lens at least during an emission period inwhich the light emitting unit emits the first wavelength light.

In the first aspect of the present disclosure, the surgical area isirradiated with the first wavelength light and the second wavelengthlight, the imaging unit that captures an image of the surgical area iscontrolled, and when the surgical area is alternately irradiated withthe first wavelength light and the second wavelength light, the wobblingoperation of the focus lens included in the imaging unit is controlledaccording to an emission timing of the first wavelength light and thesecond wavelength light.

In the second aspect of the present disclosure, the subject isirradiated with the first wavelength light and the second wavelengthlight, the imaging unit that captures an image of the subject iscontrolled, and in the wobbling operation of the focus lens included inthe imaging unit, the focus lens is not moved at least during theemission period in which the light emitting unit emits the firstwavelength light.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a configuration example of a medicalobservation system according to the present embodiment.

FIG. 2 is a block diagram illustrating a configuration example of acamera head and a control apparatus.

FIG. 3 is a diagram for describing an AF function control method.

FIG. 4 is a diagram for describing special light observation.

FIG. 5 is a diagram for describing an example of a wobbling operation.

FIG. 6 is a diagram illustrating another configuration example of themedical observation system according to the present embodiment.

FIG. 7 is a diagram illustrating a configuration example of an imagingapparatus according to the present embodiment.

FIG. 8 is a block diagram illustrating a hardware configuration exampleof the control apparatus.

DESCRIPTION OF EMBODIMENTS

Hereinafter, modes for implementing the present disclosure (hereinafterreferred to as embodiments) will be described. Note that descriptionwill be provided in the following order.

1. System configuration

2. Example of wobbling operation

3. Modified example

4. Application example

5. Hardware configuration

1. System Configuration

(Configuration Example of Medical Observation System)

FIG. 1 is a diagram illustrating a configuration example of a medicalobservation system according to the present embodiment.

FIG. 1 illustrates an example of an endoscopic surgical system used inabdominal endoscopic surgery performed in place of conventional opensurgery in a medical field.

A medical observation system 1 includes an inserting portion 11, a lightsource apparatus 12, a light guide 13, a camera head (an imaging unit)14, a first transmission cable 15, a display apparatus 16, a secondtransmission cable 17, a control apparatus 18, a third transmissioncable 19, a connector 20, and a connector 21. The combination of theinserting portion 11 and the camera head 14 may be referred to as anendoscope. The endoscope may also include at least one of the insertingportion 11, the light source apparatus 12, the light guide 13, the firsttransmission cable 15, the display apparatus 16, the second transmissioncable 17, the control apparatus 18, the third transmission cable 19, theconnector 20 and the connector 21.

The inserting portion 11 is configured as a rigid mirror or a flexiblemirror (for example, a fiberscope), for example. The inserting portion11 is a member that is hard or at least partially soft, has an elongatedshape, and is inserted into a living body. An optical system thatincludes one or a plurality of lenses and condenses a subject image isprovided in the inserting portion 11. The inserting portion 11 and thecamera head 14 may be integrated.

One end of the light guide 13 is connected to the light source apparatus12. The light source apparatus 12 supplies light for illuminating theinside of the living body to one end of the light guide 13 under thecontrol of the control apparatus 18.

The light guide 13 has one end detachably attached to the light sourceapparatus 12 and has the other end detachably attached to the insertingportion 11. The light guide 13 transmits the light supplied from thelight source apparatus 12 to one end to the other end to supply thelight to the inserting portion 11. The light supplied to the insertingportion 11 is emitted from a tip of the inserting portion 11 to theinside of the living body. Light (subject image) emitted to the livingbody and reflected from the inside of the living body is condensed bythe optical system in the inserting portion 11.

The camera head 14 is detachably connected to an eyepiece portion 11Awhich is a proximal end of the inserting portion 11. The camera head 14captures the subject image condensed by the inserting portion 11 andoutputs image data (RAW data) under the control of the control apparatus18. The image data is image data of 4K or more, for example.

Hereinafter, an image based on the image data is also referred to as acaptured image.

The first transmission cable 15 has one end detachably connected to thecontrol apparatus 18 via the connector 20 and has the other enddetachably connected to the camera head 14 via the connector 21. Thefirst transmission cable 15 transmits image data and the like outputfrom the camera head 14 to the control apparatus 18 and transmits acontrol signal, a synchronization signal, a clock signal, and anelectric power output from the control apparatus 18 to the camera head14. A memory may be mounted on, or included in, the connector 20 or theconnector 21, and parameters related to the camera head 14 and thecontrol apparatus 18 may be stored in the memory. For example, thefactory parameters of the camera head 14 and the parameters changed whenthe power is turned on may be stored in the memory, and the operation ofthe camera head may be changed based on the parameters read from thememory.

The image data and the like transmitted from the camera head 14 to thecontrol apparatus 18 via the first transmission cable 15 may be anoptical signal or an electrical signal. The same applies to transmissionof the control signal, the synchronization signal, and the clock signalfrom the control apparatus 18 to the camera head 14 via the firsttransmission cable 15.

The display apparatus 16 displays a display image based on a videosignal output from the control apparatus 18 under the control of thecontrol apparatus 18.

The second transmission cable 17 has one end detachably connected to thedisplay apparatus 16 and has the other end detachably connected to thecontrol apparatus 18. The second transmission cable 17 transmits a videosignal processed by the control apparatus 18 and a control signal outputfrom the control apparatus 18 to the display apparatus 16.

The control apparatus 18 is configured as a camera control unit (CCU),for example, and includes a circuit including a CPU (Central ProcessingUnit) and the like. The control apparatus 18 integrally controls theoperations of the light source apparatus 12, the camera head 14, and thedisplay apparatus 16.

The third transmission cable 19 has one end detachably connected to thelight source apparatus 12 and has the other end detachably connected tothe control apparatus 18. The third transmission cable 19 transmits thecontrol signal from the control apparatus 18 to the light sourceapparatus 12.

(Configuration Example of Camera Head and Control Apparatus)

Next, a configuration example of the camera head 14 and the controlapparatus 18 will be described with reference to FIG. 2 .

The camera head 14 includes a lens unit 31, a lens driving unit 32, andan imaging processing unit 33.

The lens unit 31 includes a plurality of lenses movable along an opticalaxis and forms a subject image condensed by the inserting portion 11 onan imaging surface of the imaging processing unit 33. The lens unit 31includes a focus lens 41 and a zoom lens 42.

The focus lens 41 includes one or a plurality of lenses and adjusts thefocus of the camera head 14 by moving along the optical axis.

The zoom lens 42 includes one or a plurality of lenses and adjusts theangle of view of the camera head 14 by moving along the optical axis.

Although not illustrated in the drawing, the lens unit 31 includes afocus mechanism that moves the focus lens 41 along the optical axis andan optical zoom mechanism that moves the zoom lens 42 along the opticalaxis.

The lens driving unit 32 includes an actuator that operates the focusmechanism and the optical zoom mechanism and a driver that drives theactuator. The lens driving unit 32 adjusts the focus and the angle ofview of the lens unit 31 under the control of the control apparatus 18.

The lens driving unit 32 includes a position sensor such as a photointerrupter. The lens driving unit 32 detects the position of the focuslens 41 and the position of the zoom lens 42 and outputs a detectionsignal corresponding to these positions to the control apparatus 18.

The imaging processing unit 33 includes a sensor chip in which animaging element and a signal processing unit are formed integrally. Theimaging element is configured, for example, as CCD (Charge CoupledDevice) or CMOS (Complementary Metal Oxide Semiconductor) and convertsthe subject image condensed by the inserting portion 11 and formed bythe lens unit 31 and converts the same to an electrical signal. Theimaging processing unit 33 performs signal processing such as A/Dconversion on the electrical signal (analog signal) from the imagingelement and outputs image data. The imaging processing unit 33 capturesan image of the inside of the living body and outputs image data(digital data) after A/D conversion under the control of the controlapparatus 18.

The imaging processing unit 33 may not be formed integrally with theimaging element but may be a separate unit. Moreover, the imagingelement preferably has a number of pixels capable of outputting imagedata of a resolution of 4K (3840×2160 pixels) or more.

The control apparatus 18 includes a signal processing unit 51, a controlunit 52, an input unit 53, an output unit 54, and a storage unit 55.

The signal processing unit 51 performs various kinds of processing onthe image data (RAW data) output from the camera head 14 under thecontrol of the control unit 52.

The signal processing unit 51 performs RAW processing such as opticalblack subtraction processing and demosaic processing on the image data(RAW data) to convert the same to RGB data. Moreover, the signalprocessing unit 51 performs RGB processing such as white balancing, RGBgamma correction, and YC conversion on the obtained RGB data.Furthermore, the signal processing unit 51 executes YC processing suchas color difference correction and noise reduction on the obtained Y andCb/Cr data. The signal processing unit 51 supplies the image data afterthe image processing to the control unit 52.

The signal processing unit 51 calculates an evaluation value forcontrolling the camera head 14 with respect to the image data (forexample, Y and Cb/Cr data) after the image processing. For example, thesignal processing unit 51 detects the contrast and the frequencycomponent of an image in a designated region on the basis of pixelinformation (luminance data (Y)) of each pixel of the designated regionin one frame of captured images captured by the imaging processing unit33. The signal processing unit 51 calculates an in-focus evaluationvalue (AF evaluation value) for evaluating an in-focus state of thecaptured image (a subject image therein) on the basis of the detectedcontrast and frequency component and supplies the calculated evaluationvalue to the control unit 52.

The control unit 52 is configured as a CPU or the like, for example, andcontrols the operations of the light source apparatus 12, the camerahead 14, and the display apparatus 16 and controls the overall operationof the control apparatus 18 by outputting a control signal. The controlunit 52 includes a focus control unit 61, an emission control unit 62,and a display control unit 63.

The focus control unit 61 adjusts the focus of the lens unit 31 (changesthe position of the focus lens 41) by operating the lens driving unit32. For example, the focus control unit 61 executes evaluationprocessing on the basis of the position of the focus lens 41 detected bythe lens driving unit 32 and the AF evaluation value from the signalprocessing unit 51. Moreover, the focus control unit 61 controls an AFoperation of the focus lens 41 on the basis of operation informationfrom the input unit 53.

The emission control unit 62 controls emission of a light emitting unit71 included in the light source apparatus 12. The light emitting unit 71emits light to irradiate a surgical area serving as a subject withnormal light such as WLI (White Light Imaging) light (for example,visible light including light having a wavelength band of 360 nm to 760nm) as light having a first wavelength band (first wavelength light) andspecial light such as IR (Infrared) light as light having a secondwavelength band (second wavelength light). Here, IR light may includeNIR (Near-infrared) light. For example, IR light may be light having awavelength band of 760 nm or more and 1000 μm or smaller.

The display control unit 63 generates a display video signal on thebasis of the image data (Y and Cb/Cr data) processed by the signalprocessing unit 51 by OSD (On Screen Display) processing or the like andoutputs the video signal to the display apparatus 16.

The input unit 53 includes an operating device such as buttons,switches, a mouse, a keyboard, and a touch panel and receives a user'soperation. The input unit 53 supplies an input signal input by theuser's operation to the control unit 52.

The output unit 54 includes a speaker, a printer, and the like andoutputs various kinds of information.

The storage unit 55 stores programs executed by the control unit 52 andinformation and the like necessary for processing of the control unit52.

The display apparatus 16 include a display device which uses liquidcrystal or organic EL (Electro Luminescence) and displays a displayimage based on the video signal output from the control apparatus 18.

(Control of AF Function)

In the medical observation system 1, three modes including a one-touchAF mode, a continuous AF mode, and a manual mode, for example, arerealized as a focus adjustment mode.

The one-touch AF mode is a mode in which AF is performed sporadicallyaccording to an operation on an operating unit (not illustrated)provided in the camera head 14, for example.

The continuous AF mode is a mode in which AF is basically performedalways (continuously). For example, the continuous AF mode is a mode inwhich AF is performed when evaluation of a captured image is performedcontinuously and an obtained evaluation value satisfies a predeterminedcondition. The continuous AF mode is switched on and off according to anoperation on the input unit 53, for example.

The manual mode is a mode in which a user moves the focus lens 41according to an operation on the input unit 53, for example.

In the one-touch AF mode and the continuous AF mode, similar processingis performed until the movement amount of the focus lens 41 isdetermined.

Here, an AF function control method will be described. As the AFfunction control method, for example, a method (so-called hill-climbingAF method) of calculating an AF evaluation value of a captured image andadjusting the position of the focus lens 41 so that the AF evaluationvalue becomes the highest is the mainstream.

The AF evaluation value of the position of the focus lens 41 ismaximized at an in-focus position. Therefore, AF can be realized bycontrolling the position of the focus lens 41 so that the AF evaluationvalue is maximized. Furthermore, a wobbling operation is performed todetermine the movement amount and the direction of moving the focus lens41 to the in-focus position.

As illustrated in FIG. 3 , regarding the focus lens 41, movement to thein-focus position according to the hill-climbing AF method and awobbling operation are performed. In FIG. 3 , the horizontal axisindicates time and the vertical axis indicates the position of the focuslens 41. The control of the timing to acquire the AF evaluation valueand the movement of lenses, and the driving instruction are executedwith reference to a vertical synchronization signal (for example, atiming corresponding to one field or one frame). In this example, it isassumed that the control and the instruction are executed with referenceto the timing corresponding to one frame.

In a wobbling operation, first, the focus lens 41 is moved by a certaindistance in a direction away from the imaging element in a first period,and the focus lens is stopped for a certain period of time in a secondperiod. Moreover, the focus lens is moved by a certain distance in adirection closer to the imaging element in a third period, and the focuslens is stopped for a certain period of time in a fourth period. Aseries of these operations from the first to fourth periods is performedrepeatedly. The period from the first to fourth periods (regardless ofthe order) is regarded as one cycle of wobbling.

The AF evaluation values in the second and fourth periods are detectedand the difference is calculated whereby a fluctuation component of theAF evaluation value due to the wobbling operation can be obtained. Bydetermining the sign (positive/negative) of the fluctuation component,the direction and the movement amount of moving the focus lens 41 to thein-focus position is determined.

In surgical endoscopes and surgical microscopes, an observation methodcalled special light observation is known. Special light observation isan observation method in which normal light such as WLI light andspecial light such as IR light are irradiated alternately to obtain animage that cannot be obtained with normal light only.

FIG. 4 is a diagram for comparing an image obtained by normal lightobservation and an image obtained by special light observation.

FIG. 4A illustrates a WLI image obtained by irradiating WLI light onlyand FIG. 4B illustrates a superimposed image in which an IR imageobtained by irradiating an IR light is superimposed on the WLI image.Since the IR image is a luminance image composed of luminance data, theIR image highlighted in a pseudo color is superimposed on the WLI image.

As illustrated in FIG. 4 , in special light observation using IR light,ICG (indocyanate green) administered to a living tissue serving as asubject is excited by IR light to generate fluorescence, and the deeppart of a blood vessel is highlighted by a luminance image obtained byreceiving the fluorescence.

In special light observation, when WLI light and IR light is irradiatedalternately, the AF evaluation value of the IR image as well as the AFevaluation value of the WLI image is calculated by the above-describedAF function.

However, since an IR image tends to be an unclear luminance image, it isnot appropriate to use the AF evaluation value of the IR image todetermine the movement amount and the direction of moving the focus lens41 by the wobbling operation.

Therefore, in the medical observation system according to the presentembodiment, a wobbling operation of the focus lens 41 is controlledaccording to an emission timing of normal light (WLI light) and speciallight (IR light).

2. Example of Wobbling Operation

An example of a wobbling operation of the focus lens 41 according to anemission timing of WLI light and IR light in the medical observationsystem 1 will be described with reference to FIG. 5 .

FIG. 5 illustrates the timings of a vertical synchronization signal,emission (IR emission) of IR light, emission (WLI emission) of WLIlight, exposure, and a wobbling operation of the focus lens 41. Althoughmovement of the focus lens 41 according to the hill-climbing AF methodas well as a wobbling operation is also illustrated in FIG. 3 , only thewobbling operation is illustrated in FIG. 5 .

As illustrated in FIG. 5 , the control unit 52 (the emission controlunit 62) controls the light emitting unit 71 so that WLI light and IRlight are alternately emitted in synchronization with a verticalsynchronization signal. In the example of FIG. 5 , the light emittingunit 71 emits WLI light or IR light in the period of the latter half(0.5) cycle of one cycle of the vertical synchronization signal.

As illustrated in FIG. 5 , exposure (readout) corresponding to anemission period of the WLI light and exposure (readout) corresponding toan emission period of the IR light are performed alternately. In thisway, the WLI image and the IR image are captured alternately.

As illustrated in FIG. 5 , a switching timing of the exposurecorresponding to the emission period of the WLI light and the exposurecorresponding to the emission period of the IR light is synchronizedwith a switching timing of a moving period and a stopping period of thefocus lens 41 in the wobbling operation.

In other words, the emission period of the WLI light and the emissionperiod of the IR light are synchronized with the moving period and thestopping period of the focus lens 41 in the wobbling operation. In thiscase, the control unit 52 (the focus control unit 61) controls thewobbling operation of the focus lens 41 according to the emissiontimings of the WLI light and the IR light. More specifically, the focuscontrol unit 61 does not move the focus lens 41 in the wobblingoperation at least during the emission period of the WLI light and movesthe focus lens 41 in the wobbling operation at least during the emissionperiod of the IR light.

The evaluation process (determination of the direction and the movementamount of the focus lens 41) using the AF evaluation value is performedin the stopping period (the exposure period of the WLI image) of thefocus lens 41 in the wobbling operation and the result thereof is usedin the subsequent movement of the focus lens 41. In the evaluationprocess, the AF evaluation value calculated from the WLI image capturedin the previous stopping period in the wobbling operation and the AFevaluation value calculated from the WLI image captured in a stoppingperiod before the previous stopping period are acquired. In theevaluation process using the AF evaluation value, an AF evaluation valuecalculated from at least two WLI images may be acquired. The focuscontrol unit 61 may perform control so that the focus lens 41 is notmoved in the wobbling operation at least during an exposure period ofpixels for receiving a WLI light and calculating an AF evaluation value.For example, when the pixels for calculating the AF evaluation valueused in the wobbling operation are pixels positioned near the center ofan imaging element, the focus lens 41 is not moved in a period in whichthe pixels positioned around the center are exposed to the WLI light,and the focus lens 41 is moved in a period in which the other pixels areexposed to the WLI light. In this way, by moving the focus lens in anexposure period of an invalid region of an endoscope image which becomesdark due to vignetting resulting from the scope, it is possible tosecure a longer moving time of the focus lens.

According to the above-described operation, the focus lens 41 is movedin the wobbling operation in an exposure period (an emission period ofthe IR light) of an IR image that is not used for calculation of the AFevaluation value. That is, since the focus lens 41 is not moved duringcapturing of a WLI image in the wobbling operation, the focus shake canbe reduced and an evaluation process (determination of the direction andthe movement amount of the focus lens 41) using the AF evaluation valuecalculated from two clear WLI images can be performed. In other words,the movement amount and direction of the focus lens 41 are calculated bycomparing the AF evaluation values of the two WLI images.

In this way, even when a wobbling operation is performed in speciallight observation in which normal light such as WLI light and speciallight such as IR light are irradiated alternately, it is possible toobtain an appropriate AF evaluation value and realize more accurate AF.

As described above, although an IR image is captured so as to correspondto an emission period of IR light, an AF evaluation value is notcalculated from the IR image. However, the AF evaluation valuecalculated from the IR image is not used in the evaluation process evenif the AF evaluation value is not stored in the storage unit 55 of thecontrol apparatus 18 or is stored in the storage unit 55. If thedifference between the two AF evaluation values is larger than apredetermined value, the wobbling operation may be reset. As a result,it is possible to reset the AF evaluation value when the AF evaluationvalue of the WLI image and the IR image is compared due to error (forexample, a synchronization error).

In the wobbling operation of the medical observation system 1 accordingto the present embodiment, as illustrated in FIG. 5 , the focus lens 41is moved in the wobbling operation with reference to the center ofbalance of the exposure period corresponding to a WLI light.Specifically, a midpoint (the center of balance of an exposure periodcorresponding to IR light) between the centers of balance of twosuccessive exposure periods (exposure periods used for calculation ofthe AF evaluation value) corresponding to WLI light coincides with amidpoint of the moving time of the focus lens 41 in the wobblingoperation. The center of balance of an exposure period may be regardedas an exposure time of pixels positioned at the center of an imagingelement.

In this way, in the evaluation process of the wobbling operation, whenthe AF evaluation values calculated from two WLI images are compared, itis possible to equalize the respective AF evaluation values.

As described above with reference to FIG. 3 , although movement of thefocus lens 41 to the in-focus position by the hill-climbing AF method aswell as the wobbling operation of the focus lens 41 is controlled, themovement of the focus lens 41 may be stopped completely during theemission period of the WLI light. In this way, the rolling shutterdistortion in the WLI image can be reduced.

3. Modified Example

(Special Light Observation Mode and Normal Light Observation Mode)

The medical observation system according to the present embodiment canoperate in a normal light observation mode in which a surgical areaserving as a subject is irradiated with normal light only in addition toa special light observation mode in which the surgical area isalternately irradiated with normal light and special light. In thenormal light observation mode, a wobbling operation is performedregardless of an emission timing or the like.

In this case, the movement amount of the focus lens in the wobblingoperation may be different from the special light observation mode andthe normal light observation mode. Moreover, the movement amount of thefocus lens in the hill-climbing AF operation may be different from thespecial light observation mode to the normal light observation mode.Here, the movement amount being different means that the focus lensmoves different distances.

For example, the movement amount of the focus lens during the emissionperiod of IR light in the wobbling operation in the special lightobservation mode may be smaller than that in the normal lightobservation mode. A user may frequently switch from the normal lightobservation mode to the special light observation mode when a region tobe observed is already in focus. Therefore, in the special lightobservation mode, it is not necessary to move the focus lens as much asin the normal light observation mode. Furthermore, by decreasing theamount of the focus lens in the wobbling operation, it is possible toreduce the influence of image distortion due to the wobbling operation.Moreover, for example, the movement amount of the hill-climbing AFoperation in the special light observation mode may be smaller than thatin the normal light observation mode. Furthermore, in the special lightobservation mode, the movement amount of the hill-climbing AF operationduring the emission period of second wavelength light may be smallerthan the movement amount of the hill-climbing AF operation during theemission period of first wavelength light. In this way, it is possibleto flexibly set the irradiation time of the second wavelength light andthe imaging frame rate of the second wavelength light. Moreover, themovement amount of the focus lens during the emission period of IR lightin the wobbling operation in the special light observation mode may belarger than that in the normal light observation mode. There is apossibility that a region to be observed by an operator may be differentfrom the normal light observation mode to the special light observationmode. Therefore, by increasing the movement amount of the focus lens inthe special light observation mode to be larger than that in the normallight observation mode, it is possible to focus on an observation targetdifferent from that of the normal light observation mode.

Since the focus in the special light observation is on the deeper sidethan the focus in the normal light observation, the focus lens in thewobbling operation in the special light observation mode may be movedcloser to the FAR side (i.e., the side further away from the objectunder observation as viewed on an optical axis of the imaging device)than in the normal light observation mode. Similarly, a referenceposition of the focus lens in the wobbling operation in the speciallight observation mode may be moved closer to the FAR side than in thenormal light observation mode.

The moving speed of the focus lens in the wobbling operation may bedifferent from the special light observation mode and the normal lightobservation mode. Moreover, the moving speed of the focus lens in thehill-climbing AF operation may be different from the special lightobservation mode and the normal light observation mode.

For example, the moving speed of the focus lens during the emissionperiod of IR light in the wobbling operation in the special lightobservation mode may be higher than that in the normal light observationmode. In this way, when it is necessary to shorten the emission periodof IR light, a sufficient wobbling operation can be performed. Moreover,for example, the moving speed of the hill-climbing AF operation in thespecial light observation mode may be higher than that in the normallight observation mode. In this way, it is possible to move the focuslens to the in-focus position more quickly while suppressing theinfluence on the evaluation value. Moreover, by increasing the movementamount during emission of normal light to be larger than during emissionof IR light, it is possible to suppress the influence of a rollingshutter while suppressing increase in focusing time and acquire a moreaccurate evaluation value. Furthermore, in the special light observationmode, the moving speed in the hill-climbing AF operation during theemission period of second wavelength light may be higher than the movingspeed in the hill-climbing AF operation during the emission period offirst wavelength light. In this way, it is possible to flexibly set theirradiation time of the second wavelength light and the imaging framerate of the second wavelength light.

As described above, when the movement amount and the moving speed of thefocus lens in the wobbling operation are different from the speciallight observation mode and the normal light observation mode, themovement amount and the moving speed in the special light observationmode may be changed according to the irradiation time of the IR light tomove the focus lens in the wobbling operation. Similarly, the movementamount and the moving speed in the special light observation mode may bechanged according to the imaging frame rate to move the focus lens inthe wobbling operation. In this way, in the special light observationmode, the irradiation time of the first wavelength light can be easilymade different from that of the second wavelength light and the framerate can be easily made different, and the degree of freedom in designcan be improved.

When it is determined by image recognition that an organ serving as asurgical site is in focus, the movement amount of the focus lens in thewobbling operation may be decreased. For the image recognition, forexample, image recognition based on machine learning using a neuralnetwork can be used. In the above-described example, the movement amountof the focus lens is determined on the basis of at least two AFevaluation values. However, the movement amount of the focus lens in thewobbling operation may be determined using machine learning. The machinelearning parameters may be changed depending on a surgical form.

(Operation in the Event of Trouble)

-   -   When IR light emission stops:

When emission of IR light stops during movement of the focus lens in thewobbling operation, rather than stopping the focus lens on the spot, thefocus lens may be moved by a specified movement amount and then bereturned to the reference position. When the special light observationmode switches to the normal light observation mode, since the obtainedcaptured image is slightly disturbed, the focus lens is returned to thereference position and is stopped for a period of time.

-   -   When fluctuation component of AF evaluation value is small:

When the fluctuation component of the AF evaluation value due to thewobbling operation is small, since there is a possibility that anevaluation process cannot be performed, the movement amount of the focuslens in the wobbling operation may be increased. In this case, the focuslens may be moved in the wobbling operation during the emission periodof WLI light as well as during the emission period of IR light.

(Operation Specialized for Endoscopic Surgical System)

-   -   Wobbling operation depending on model:

The movement amount of the focus lens in the wobbling operation may bechanged depending on a connected inserting portion (scope) or camerahead. For example, a small-diameter scope used in otorhinology has adeeper depth of field than a large-diameter scope used in laparoscopicsurgery. Therefore, in order to obtain a highly accurate AF evaluationvalue, the movement amount of the focus lens in the wobbling operationmay be increased. Moreover, when the control apparatus stores aplurality of modes according to a surgical form, the control apparatusmay change the movement amount of the focus lens in the wobblingoperation according to the mode of the surgical form selected by theuser. For example, when the surgical form includes an “arthroscopymode”, a “cystoscopy mode”, an “otolaryngology/skull examination mode”,a “hysteroscopy mode”, and a “laparoscopic examination mode”, themovement amount of the focus lens in the wobbling operation may bechanged for each mode.

-   -   Wobbling operation according to diameter of inserting portion:

The number of movements of the focus lens in the wobbling operation maybe changed depending on the diameter of a connected inserting portion(scope) and a camera head. For example, a small-diameter scope used inotorhinology has a deeper depth of field than a large-diameter scopeused in laparoscopic surgery. Therefore, in order to obtain a highlyaccurate AF evaluation value, the number of movements of the focus lensin the wobbling operation may be increased.

-   -   Wobbling operation according to insertion/removal of inserting        portion:

The insertion/removal of the inserting portion (scope) may be detected,and the wobbling operation may be stopped when removal of the scope isdetected during the wobbling operation. In this way, it is possible toprevent the actuator from being damaged by the removal movement.Moreover, it is preferable that the wobbling operation is not performedeven when the scope is being removed.

-   -   Wobbling operation according to connection state of inserting        portion:

The connection between the inserting portion (scope) and the camera headmay be detected, and the wobbling operation may not be performed whenconnection of the scope is not detected due to replacement or the likeof the scope.

(Wavelength Band of Light Emitted by Light Emitting Unit)

In the above-description, it is assumed that WLI light (normal light) isirradiated as the first wavelength light, and IR light (special light)is irradiated as the second wavelength light. However, there is nolimitation thereto, and for example, blue light may be irradiated as thefirst wavelength light, and green light or ultraviolet light may beirradiated as the second wavelength light. Moreover, during theirradiation time of the second wavelength light, IR light andultraviolet light may be irradiated simultaneously and the IR light andthe ultraviolet light may be irradiated sequentially.

4. Application Example

(Surgical Video Microscope Apparatus)

Next, an example in which a surgical video microscope apparatusincluding an arm is used will be described as another applicationexample of the medical observation system according to the presentembodiment with reference to FIG. 6 .

FIG. 6 illustrates an example of a microscopic surgical system whichuses a surgical video microscope apparatus as an observation medicaldevice for observing the inside of a patient.

FIG. 6 illustrates a state in which a physician who is an operator(user) 220 performs an operation on an operation target (patient) 240 onan operating table 230 using an operation instrument 221 such as, forexample, a scalpel, tweezers, and forceps.

In the following description, the term “operation” refers to a generalterm for various medical treatments, such as surgery and examination,that the physician who is the user 220 performs on a patient who is theoperation target 240. In the example of FIG. 6 , although the situationof surgery is illustrated as an example of an operation, the operationused by the surgical video microscope apparatus 210 is not limited tosurgery but may be various other operations.

The surgical video microscope apparatus 210 according to the presentembodiment is provided beside the operating table 230.

The surgical video microscope apparatus 210 includes a base portion 211as a base, an arm portion 212 extending from the base portion 211, andan imaging unit 215 connected to a tip of the arm portion 212 as a tipunit.

The arm portion 212 includes a plurality of joint portions 213 a, 213 b,and 213 c, a plurality of links 214 a and 214 b connected by the jointportions 213 a and 213 b, and the imaging unit 215 provided at the tipof the arm portion 212.

In the example of FIG. 6 , for simplicity, the arm portion 212 has threejoint portions 213 a to 213 c and two links 214 a and 214 b.Practically, in consideration of the degree of freedom in the positionand the posture of the arm portion 212 and the imaging unit 215, thenumbers and the shapes of the joint portions 213 a to 213 c and thelinks 214 a and 214 b and the direction of the driving shaft of thejoint portions 213 a to 213 c may be set appropriate so that a desireddegree of freedom is realized.

The joint portions 213 a to 213 c have a function of rotatablyconnecting the links 214 a and 214 b, and the driving of the arm portion212 is controlled by driving the rotation of the joint portions 213 a to213 c.

The imaging unit 215 as a tip unit is connected to the tip of the armportion 212.

The imaging unit 215 is a unit that acquires an imaging target image byincluding an optical system for acquiring an optical image of a subjectand is configured as a camera or the like capable of capturing a movingimage and a still image, for example. As illustrated in FIG. 6 , theposture and the position of the arm portion 212 and the imaging unit 215are controlled by the surgical video microscope apparatus 210 so thatthe imaging unit 215 provided at the tip of the arm portion 212 capturesthe image of the state of the operating region of the operation target240.

The configuration of the imaging unit 215 connected to the distal end ofthe arm portion 212 as a tip unit is not particularly limited, and forexample, the imaging unit 215 may be configured as an endoscope or amicroscope. Moreover, the imaging unit 215 may be configured to bedetachably attached to the arm portion 212.

With such a configuration, for example, an imaging unit 215corresponding to the purpose of use may be appropriately connected tothe tip of the arm portion 212 as a tip unit. Although a case in whichthe imaging unit 215 is applied as the tip unit will be described, thetip unit connected to the tip of the arm portion 212 is naturally notlimited to the imaging unit 215.

A display apparatus 250 such as a monitor or a display is provided at aposition facing the user 220. The image of the operating region acquiredby the imaging unit 215 is processed by an image processing apparatusincorporated in or externally attached to the surgical video microscopeapparatus 210, for example, and is displayed on the display screen ofthe display apparatus 250 as an electronic image.

With such a configuration, the user 220 can perform various treatments(for example, surgery or the like) while viewing the electronic image ofthe operating portion displayed on the display screen of the displayapparatus 250.

Here, in the example of FIG. 6 , the imaging unit 215 includes thecamera head 14 and the light source apparatus 12 (the light emittingunit 71) described with reference to FIG. 2 , for example. Moreover, theimage processing apparatus that performs various kinds of imageprocessing on the image of the operating region acquired by the imagingunit 215 corresponds to an example of the control apparatus describedwith reference to FIG. 2 . Similarly, the display apparatus 250corresponds to an example of the display apparatus 16 described withreference to FIG. 2 .

(General Imaging System)

The technology according to the present disclosure is not limited to themedical observation system but can be applied to a general imagingsystem.

FIG. 7 illustrates a configuration example of an imaging apparatus whichis an example of a general imaging system. An imaging apparatus 310 inFIG. 7 is configured as a consumer camera, for example.

The imaging apparatus 310 includes a lens unit 331, a lens driving unit332, an imaging processing unit 333, a signal processing unit 351, acontrol unit 352, an input unit 353, an output unit 354, a storage unit355, and a light emitting unit 356.

The lens unit 331, the lens driving unit 332, and the imaging processingunit 333 correspond to the lens unit 31, the lens driving unit 32, andthe imaging processing unit 33 included in the camera head 14illustrated in FIG. 2 . That is, a focus lens 341 and a zoom lens 342included in the lens unit 331 also correspond to the focus lens 41 andthe zoom lens 42 included in the lens unit 31 illustrated in FIG. 2 .

The signal processing unit 351, the control unit 352, the input unit353, the output unit 354, and the storage unit 355 correspond to thesignal processing unit 51, the control unit 52, the input unit 53, theoutput unit 54, and the storage unit 55 included in the controlapparatus 18 illustrated in FIG. 2 . That is, a focus control unit 361,an emission control unit 362, and a display control unit 363 included inthe control unit 352 also correspond to the focus control unit 61, theemission control unit 62, and the display control unit 63 included inthe control unit 52 illustrated in FIG. 2 .

The light emitting unit 356 corresponds to the light emitting unit 71included in the light source apparatus 12 illustrated in FIG. 2 .

In the above-described configuration, even when a wobbling operation isperformed in an observation mode in which first wavelength light (normallight) and second wavelength light (special light) are alternatelyirradiated, it is possible to obtain an appropriate AF evaluation valueand realize more accurate AF.

5. Hardware Configuration

Next, an example of a hardware configuration of a control apparatus thatconstitutes the medical observation system according to the presentembodiment will be described in detail with reference to FIG. 8 .

FIG. 8 is a block diagram for illustrating an example of the hardwareconfiguration of the control apparatus 500 that constitutes the medicalobservation system according to the present embodiment.

As illustrated in FIG. 8 , the control apparatus 500 includes a CPU 501,a ROM 503, and a RAM 505. Furthermore, the control apparatus 500 alsoincludes a host bus 507, a bridge 509, an external bus 511, an interface513, an input apparatus 515, an output apparatus 517, and a storageapparatus 519. The control apparatus 500 may further include a drive521, a connection port 523, and a communication apparatus 525.

The CPU 501 functions as an arithmetic processing apparatus and acontrol apparatus, and controls the overall operation or a part of theoperation of the control apparatus 500 according to various programsrecorded in the ROM 503, the RAM 505, the storage apparatus 519, or aremovable recording medium 527.

The ROM 503 stores programs, operation parameters, and the like used bythe CPU 501. The RAM 505 primarily stores programs used by the CPU 501and parameters and the like varying as appropriate during the executionof the programs. These components are connected with each other via thehost bus 507 configured as an internal bus such as a CPU bus or thelike. The respective configurations of the control unit 52 of thecontrol apparatus 18 described with reference to FIG. 2 are realized bythe CPU 501, for example.

The host bus 507 is connected to the external bus 511 such as a PCI(Peripheral Component Interconnect/Interface) bus via the bridge 509.The input apparatus 515, the output apparatus 517, the storage apparatus519, the drive 521, the connection port 523, and the communicationapparatus 525 are connected to the external bus 511 via the interface513.

The input apparatus 515 is an operating unit operated by a user, suchas, for example, a mouse, a keyboard, a touch panel, buttons, a switch,a lever, and a pedal. The input apparatus 515 may be a remote controlunit (so-called a remote control) using, for example, infrared rays orother radio waves, or may be an externally connected apparatus 529 suchas a mobile phone or a PDA conforming to the operation of the controlapparatus 500.

For example, the input apparatus 515 generates an input signal on thebasis of, for example, information input by a user using theabove-described operating unit, and is configured as an input controlcircuit for outputting the input signal to the CPU 501.

The user can input various kinds of data to the control apparatus 500and can instruct the control apparatus 500 to perform processing byoperating the input apparatus 515.

The output apparatus 517 is configured as an apparatus capable ofvisually or audibly notifying the user of acquired information.Specifically, the output apparatus 517 include a display apparatus suchas a CRT display apparatus, a liquid crystal display apparatus, a plasmadisplay apparatus, an EL display apparatus, and lamps, an audio outputapparatus such as a speaker and a headphone, a printer, and the like.

For example, the output apparatus 517 outputs a result obtained byvarious kinds of processing performed by the control apparatus 500.Specifically, the display apparatus displays the result obtained byvarious kinds of processing performed by the control apparatus 500 inthe form of text or images. On the other hand, the audio outputapparatus converts an audio signal such as reproduced audio data andacoustic data into an analog signal, and outputs the analog signal. Thelight source apparatus 12 and the display apparatus 16 described withreference to FIG. 2 are realized by the output apparatus 517, forexample.

The storage apparatus 519 is an apparatus for storing data configured asan example of a storage unit of the control apparatus 500. The storageapparatus 519 is configured as, for example, a magnetic storage devicesuch as an HDD (Hard Disk Drive), a semiconductor storage device, anoptical storage device, or a magneto-optical storage device. The storageapparatus 519 stores programs to be executed by the CPU 501, variouskinds of data, and the like.

The drive 521 is a reader/writer for recording medium, and is embeddedin the control apparatus 500 or attached externally thereto. The drive521 reads information recorded in the attached removable recordingmedium 527 such as a magnetic disk, an optical disc, a magneto-opticaldisk, or a semiconductor memory, and outputs the read information to theRAM 505. Furthermore, the drive 521 can write data to the attachedremovable recording medium 527 such as a magnetic disk, an optical disc,a magneto-optical disk, or a semiconductor memory.

The removable recording medium 527 is, for example, a DVD medium, anHD-DVD medium, or a Blu-ray (registered trademark) medium. The removablerecording medium 527 may be a CompactFlash (registered trademark), aflash memory, an SD (Secure Digital) memory card, or the like.Alternatively, the removable recording medium 527 may be, for example,an IC (Integrated Circuit) card equipped with a non-contact IC chip oran electronic appliance.

The connection port 523 is a port for directly connecting the externallyconnected apparatus 529 to the control apparatus 500. Examples of theconnection port 523 include a USB (Universal Serial Bus) port, anIEEE1394 port, a SCSI (Small Computer System Interface) port, and thelike. Other examples of the connection port 523 include an RS-232C port,an optical audio terminal, an HDMI (registered trademark)(High-Definition Multimedia Interface) port, and the like. By connectingthe externally connected apparatus 529 to the connection port 523, thecontrol apparatus 500 obtains various kinds of data directly from theexternally connected apparatus 529 and provides various kinds of data tothe externally connected apparatus 529.

The communication apparatus 525 is a communication interface configuredas, for example, a communication device for connecting to acommunication network 531. The communication apparatus 525 is, forexample, a wired or wireless LAN (Local Area Network), Bluetooth(registered trademark), a communication card for WUSB (Wireless USB), orthe like. Alternatively, the communication apparatus 525 may be a routerfor optical communication, a router for ADSL (Asymmetric DigitalSubscriber Line), a modem for various communications, or the like.

The communication apparatus 525 can transmit and receive signals and thelike in accordance with a predetermined protocol such as TCP/IP to andfrom the Internet and other communication apparatuses, for example. Thecommunication network 531 connected to the communication apparatus 525is configured as a network and the like, which is connected via wire orwirelessly. The communication network 531 may be, for example, theInternet and a home LAN and may be a communication network that performsinfrared communication, radio wave communication, or satellitecommunication.

Each of the components of the above-described control apparatus 500 maybe configured using a general-purpose member, or may be configured ashardware dedicated to the function of each component. Accordingly, thehardware configuration to be used can be changed as appropriateaccording to the technical level at the time of carrying out the presentembodiment.

A computer program for realizing each function of the control apparatus500 that constitutes the medical observation system according to thepresent embodiment can be produced and be implemented on a personalcomputer or the like. Moreover, a computer-readable recording medium inwhich such a computer program is stored can be provided. The recordingmedium is, for example, a magnetic disk, an optical disc, amagneto-optical disk, a flash memory, or the like. In addition, thecomputer program may be delivered via a network, for example, withoutusing a recording medium.

Note that an embodiment of the present disclosure is not limited to theabove-described embodiment, but various alterations can be made withinthe scope not departing from the spirit of the present disclosure.

For example, the present disclosure may take the configuration of cloudcomputing in which one function is shared by a plurality of apparatusesvia a network and is processed in cooperation.

Further, each step described in the above-described flowchart may beexecuted by one apparatus, and may be shared and executed by a pluralityof apparatuses.

In addition, when one step includes a plurality of processes, theplurality of processes included in the one step may be executed by oneapparatus, and may be shared and executed by a plurality of apparatuses.

Note that, the following configurations also fall within the technicalscope of the present disclosure.

(1)

A medical observation system comprising:

a light emitting unit that irradiates a surgical area with firstwavelength light and second wavelength light; and

a control unit that controls an imaging unit that captures an image ofthe surgical area, wherein

the control unit controls a wobbling operation of a focus lens includedin the imaging unit according to an emission timing of the firstwavelength light and the second wavelength light when the surgical areais alternately irradiated with the first wavelength light and the secondwavelength light.

(2)

The medical observation system according to (1), wherein

the control unit moves the focus lens in the wobbling operation at leastduring an emission period of the second wavelength light.

(3)

The medical observation system according to (2), wherein

the control unit does not move the focus lens in the wobbling operationat least during an exposure period of pixels for receiving the firstwavelength light and calculating an AF evaluation value.

(4)

The medical observation system according to (2), wherein

the control unit does not move the focus lens in the wobbling operationat least during an emission period of the first wavelength light.

(5)

The medical observation system according to (2), wherein

the control unit moves the focus lens in the wobbling operation withreference to a center of balance of an exposure period corresponding tothe first wavelength light.

(6)

The medical observation system according to (5), wherein

the control unit performs control so that a midpoint between the centersof balance of two successive exposure periods coincides with a midpointof a moving time of the focus lens in the wobbling operation.

(7)

The medical observation system according to any one of (2) to (6),wherein

the control unit controls movement of the focus lens to an in-focusposition together with the wobbling operation of the focus lens.

(8)

The medical observation system according to (7), wherein

the control unit completely stops movement of the focus lens during theemission period of the first wavelength light.

(9)

The medical observation system according to any one of (2) to (8),wherein

the control unit performs control so that a movement amount of the focuslens in the wobbling operation is different from a first mode in whichthe surgical area is alternately irradiated with the first wavelengthlight and the second wavelength light to a second mode in which thesaturation region is irradiated with the first wavelength light only.

(10)

The medical observation system according to (9), wherein

the control unit performs control so that the movement amount of thefocus lens in the wobbling operation in the first mode is smaller thanthat in the second mode.

(11)

The medical observation system according to (9), wherein

the control unit performs control so that the focus lens in the wobblingoperation in the first mode is moved closer to the FAR side than in thesecond mode.

(12)

The medical observation system according to any one of (2) to (8),wherein

the control unit performs control so that a moving speed of the focuslens in the wobbling operation is different from a first mode in whichthe surgical area is alternately irradiated with the first wavelengthlight and the second wavelength light to a second mode in which thesaturation region is irradiated with the first wavelength light only.

(13)

The medical observation system according to (12), wherein

the control unit performs control so that a moving speed of the focuslens in the wobbling operation in the first mode is larger than that inthe second mode.

(14)

The medical observation system according to any one of (2) to (8),wherein

the control unit changes at least one of a movement amount of the focuslens, a moving speed of the focus lens, and a moving timing of the focuslens in the wobbling operation according to an irradiation time of thesecond wavelength light.

(15)

The medical observation system according to any one of (2) to (8),wherein

the control unit changes at least one of a movement amount of the focuslens in the wobbling operation, a moving speed of the focus lens, and amoving timing of the focus lens in the wobbling operation according toan imaging frame rate.

(16)

The medical observation system according to any one of (1) to (15),wherein

the first wavelength light is visible light, and

the second wavelength light is IR light.

(17)

The medical observation system according to any one of (1) to (15),wherein

the first wavelength light is blue light, and

the second wavelength light is green light.

(18)

A control apparatus comprising:

a light emitting unit that irradiates a surgical area with firstwavelength light and second wavelength light; and

a control unit that controls an imaging unit that captures an image ofthe surgical area, wherein

the control unit controls a wobbling operation of a focus lens includedin the imaging unit according to an emission timing of the firstwavelength light and the second wavelength light when the surgical areais alternately irradiated with the first wavelength light and the secondwavelength light.

(19)

A control method in a control apparatus including:

a light emitting unit that irradiates a surgical area with firstwavelength light and second wavelength light; and

a control unit that controls an imaging unit that captures an image ofthe surgical area, the method comprising:

allowing the control unit to control a wobbling operation of a focuslens included in the imaging unit according to an emission timing of thefirst wavelength light and the second wavelength light when the surgicalarea is alternately irradiated with the first wavelength light and thesecond wavelength light.

(20)

An imaging apparatus comprising:

a light emitting unit that irradiates a subject with first wavelengthlight and second wavelength light; and

a control unit that controls an imaging unit that captures an image ofthe subject, wherein

in a wobbling operation of a focus lens included in the imaging unit,the control unit does not move the focus lens at least during anemission period in which the light emitting unit emits the firstwavelength light.

Note that, the following configurations also fall within the technicalscope of the present disclosure.

(1)

A medical observation system comprising:

a non-transitory computer medium including computer programinstructions, which when executed by circuitry, cause the circuitry to

control a light emitting device configured to irradiate a surgical areawith first wavelength light and second wavelength light;

control an imaging device configured to capture an image of the surgicalarea; and

control a wobbling operation of a focus lens included in the imagingdevice according to an emission timing of the first wavelength light andthe second wavelength light when the surgical area is alternatelyirradiated with the first wavelength light and the second wavelengthlight.

(2)

The medical observation system of (1), wherein

the computer program instructions, when executed by the circuitry, causethe circuitry

to move the focus lens in the wobbling operation at least during anemission period of the second wavelength light.

(3)

The medical observation system of (2), wherein the computer programinstructions, when executed by the circuitry, cause the circuitry to:

not move the focus lens in the wobbling operation at least during anexposure period of pixels for receiving the first wavelength light; and

calculate an AF evaluation value.

(4)

The medical observation system of (2), wherein

the computer program instructions, when executed by the circuitry, causethe circuitry to not move the focus lens in the wobbling operation atleast during an emission period of the first wavelength light.

(5)

The medical observation of (2), wherein

the computer program instructions, when executed by the circuitry, causethe circuitry to move the focus lens in the wobbling operation withreference to a center of balance of an exposure period corresponding tothe first wavelength light.

(6)

The medical observation system of (5), wherein

the computer program instructions, when executed by the circuitry, causethe circuitry to perform control so that a midpoint between the centersof balance of two successive exposure periods coincides with a midpointof a moving time of the focus lens in the wobbling operation.

(7)

The medical observation system of (2), wherein

the computer program instructions, when executed by the circuitry, causethe circuitry to control movement of the focus lens to an in-focusposition together with the wobbling operation of the focus lens.

(8)

The medical observation system according to (7), wherein

the computer program instructions, when executed by the circuitry, causethe circuitry to stop movement of the focus lens during the emissionperiod of the first wavelength light.

(9)

The medical observation system of (2), wherein

the computer program instructions, when executed by the circuitry, causethe circuitry to perform control so that a movement amount of the focuslens in the wobbling operation is different between a first mode inwhich the surgical area is alternately irradiated with the firstwavelength light and the second wavelength light and a second mode inwhich the surgical region is irradiated with only the first wavelengthlight.

(10)

The medical observation system of (9), wherein

the computer program instructions, when executed by the circuitry, causethe circuitry to perform control so that the movement amount of thefocus lens in the wobbling operation in the first mode is smaller thanthe movement amount of the focus lens in the second mode.

(11)

The medical observation system of (9), wherein

the computer program instructions, when executed by the circuitry, causethe circuitry to perform control so that the focus lens in the wobblingoperation in the first mode is moved further away from the surgical areathan in the second mode.

(12)

The medical observation system of (2), wherein

the computer program instructions, when executed by the circuitry, causethe circuitry to perform control so that a moving speed of the focuslens in the wobbling operation is different between a first mode inwhich the surgical area is alternately irradiated with the firstwavelength light and the second wavelength light and a second mode inwhich the saturation region is irradiated with the first wavelengthlight only.

(13)

The medical observation system of (12), wherein

the computer program instructions, when executed by the circuitry, causethe circuitry to perform control so that a moving speed of the focuslens in the wobbling operation in the first mode is larger than a movingspeed of the focus lens in the second mode.

(14)

The medical observation system of (2), wherein

the computer program instructions, when executed by the circuitry, causethe circuitry to change at least one of a movement amount of the focuslens, a moving speed of the focus lens, and a moving timing of the focuslens in the wobbling operation according to an irradiation time of thesecond wavelength light.

(15)

The medical observation system of (2), wherein

the computer program instructions, when executed by the circuitry, causethe circuitry to change at least one of a movement amount of the focuslens in the wobbling operation, a moving speed of the focus lens, and amoving timing of the focus lens in the wobbling operation according toan imaging frame rate.

(16)

The medical observation system of (1), wherein

the first wavelength light is visible light, and

the second wavelength light is IR light.

(17)

The medical observation system of (1), wherein

the first wavelength light is blue light, and

the second wavelength light is green light.

(18)

The medical observation system of (1), further comprising:

the circuitry configured to execute the computer program instructionsstored in the non-transitory computer readable medium.

(19)

The medical observation system of (1), further comprising:

an interface that is communicatively coupled to the circuitry configuredto execute the computer program instructions stored in thenon-transitory computer readable medium.

(20)

The medical observation system of (1), wherein the computer programinstructions, when executed by the circuitry, cause the circuitry to:determine a first auto-focus evaluation value for a first image capturedby the imaging device by receiving reflected light of the firstwavelength light when the focus lens of the imaging device is in a firstposition; and determine a second auto-focus evaluation value for asecond image, which is different from the first image, captured by theimaging device by receiving reflected light of the first wavelengthlight when the focus lens of the imaging device is in a second position,which is different from the first position.

(21)

The medical observation system of (1), wherein

the computer program instructions, when executed by the circuitry, causethe circuitry to reset the wobbling operation when a difference betweenthe first auto-focus evaluation and the second auto-focus evaluationvalue is greater than a predetermined threshold value.

(22)

An apparatus comprising:

circuitry configured to

obtain a plurality of images captured by an imaging device during aperiod of time during which a first wavelength light and a secondwavelength light are alternately irradiated;

determine auto-focus evaluation values of at least a first image and asecond image each captured by receiving reflected light of the firstwavelength light, wherein the first image and the second image arecaptured with a focus lens of the imaging device in different positions;and

determine a movement amount and movement direction of the focus lens bycomparing the auto-focus evaluation values of the at least the firstimage and the second image.

(23)

A medical observation method performed by a medical observation systemincluding a light emitting device that irradiates a surgical area withfirst wavelength light and second wavelength light, and circuitryconfigured to control an imaging device that captures an image of thesurgical area, the method comprising:

controlling a wobbling operation of a focus lens included in the imagingdevice according to an emission timing of the first wavelength light andthe second wavelength light when the surgical area is alternatelyirradiated with the first wavelength light and the second wavelengthlight.

(24)

An imaging apparatus comprising:

a light emitting device that irradiates a subject with first wavelengthlight and second wavelength light; and

circuitry configured to control an imaging device that captures an imageof the subject, wherein

in a wobbling operation of a focus lens included in the imaging device,the circuitry performs control to not move the focus lens at leastduring an emission period in which the light emitting unit emits thefirst wavelength light.

REFERENCE SIGNS LIST

-   -   1 Medical observation system    -   11 Inserting portion    -   12 Light source apparatus    -   14 Camera head    -   16 Display apparatus    -   18 Control apparatus    -   31 Lens unit    -   41 Focus lens    -   52 Control unit    -   61 Focus control unit    -   62 Emission control unit    -   71 Light emitting unit

1. A medical observation system comprising: a non-transitory computermedium including computer program instructions, which when executed bycircuitry, cause the circuitry to control a light emitting deviceconfigured to irradiate a surgical area with first wavelength light andsecond wavelength light; control an imaging device configured to capturean image of the surgical area; and control a wobbling operation of afocus lens included in the imaging device according to an emissiontiming of the first wavelength light and the second wavelength lightwhen the surgical area is alternately irradiated with the firstwavelength light and the second wavelength light.
 2. The medicalobservation system of claim 1, wherein the computer programinstructions, when executed by the circuitry, cause the circuitry tomove the focus lens in the wobbling operation at least during anemission period of the second wavelength light.
 3. The medicalobservation system of claim 2, wherein the computer programinstructions, when executed by the circuitry, cause the circuitry to:not move the focus lens in the wobbling operation at least during anexposure period of pixels for receiving the first wavelength light; andcalculate an AF evaluation value.
 4. The medical observation system ofclaim 2, wherein the computer program instructions, when executed by thecircuitry, cause the circuitry to not move the focus lens in thewobbling operation at least during an emission period of the firstwavelength light.
 5. The medical observation of claim 2, wherein thecomputer program instructions, when executed by the circuitry, cause thecircuitry to move the focus lens in the wobbling operation withreference to a center of balance of an exposure period corresponding tothe first wavelength light.
 6. The medical observation system of claim5, wherein the computer program instructions, when executed by thecircuitry, cause the circuitry to perform control so that a midpointbetween the centers of balance of two successive exposure periodscoincides with a midpoint of a moving time of the focus lens in thewobbling operation.
 7. The medical observation system of claim 2,wherein the computer program instructions, when executed by thecircuitry, cause the circuitry to control movement of the focus lens toan in-focus position together with the wobbling operation of the focuslens.
 8. The medical observation system according to claim 7, whereinthe computer program instructions, when executed by the circuitry, causethe circuitry to stop movement of the focus lens during the emissionperiod of the first wavelength light.
 9. The medical observation systemof claim 2, wherein the computer program instructions, when executed bythe circuitry, cause the circuitry to perform control so that a movementamount of the focus lens in the wobbling operation is different betweena first mode in which the surgical area is alternately irradiated withthe first wavelength light and the second wavelength light and a secondmode in which the surgical region is irradiated with only the firstwavelength light.
 10. The medical observation system of claim 9, whereinthe computer program instructions, when executed by the circuitry, causethe circuitry to perform control so that the movement amount of thefocus lens in the wobbling operation in the first mode is smaller thanthe movement amount of the focus lens in the second mode.
 11. Themedical observation system of claim 9, wherein the computer programinstructions, when executed by the circuitry, cause the circuitry toperform control so that the focus lens in the wobbling operation in thefirst mode is moved further away from the surgical area than in thesecond mode.
 12. The medical observation system of claim 2, wherein thecomputer program instructions, when executed by the circuitry, cause thecircuitry to perform control so that a moving speed of the focus lens inthe wobbling operation is different between a first mode in which thesurgical area is alternately irradiated with the first wavelength lightand the second wavelength light and a second mode in which thesaturation region is irradiated with the first wavelength light only.13. The medical observation system of claim 12, wherein the computerprogram instructions, when executed by the circuitry, cause thecircuitry to perform control so that a moving speed of the focus lens inthe wobbling operation in the first mode is larger than a moving speedof the focus lens in the second mode.
 14. The medical observation systemof claim 2, wherein the computer program instructions, when executed bythe circuitry, cause the circuitry to change at least one of a movementamount of the focus lens, a moving speed of the focus lens, and a movingtiming of the focus lens in the wobbling operation according to anirradiation time of the second wavelength light.
 15. The medicalobservation system of claim 2, wherein the computer programinstructions, when executed by the circuitry, cause the circuitry tochange at least one of a movement amount of the focus lens in thewobbling operation, a moving speed of the focus lens, and a movingtiming of the focus lens in the wobbling operation according to animaging frame rate.
 16. The medical observation system of claim 1,wherein the first wavelength light is visible light, and the secondwavelength light is IR light.
 17. The medical observation system ofclaim 1, wherein the first wavelength light is blue light, and thesecond wavelength light is green light.
 18. The medical observationsystem of claim 1, further comprising: the circuitry configured toexecute the computer program instructions stored in the non-transitorycomputer readable medium.
 19. The medical observation system of claim 1,further comprising: an interface that is communicatively coupled to thecircuitry configured to execute the computer program instructions storedin the non-transitory computer readable medium.
 20. The medicalobservation system of claim 1, wherein the computer programinstructions, when executed by the circuitry, cause the circuitry to:determine a first auto-focus evaluation value for a first image capturedby the imaging device by receiving reflected light of the firstwavelength light when the focus lens of the imaging device is in a firstposition; and determine a second auto-focus evaluation value for asecond image, which is different from the first image, captured by theimaging device by receiving reflected light of the first wavelengthlight when the focus lens of the imaging device is in a second position,which is different from the first position.
 21. The medical observationsystem of claim 1, wherein the computer program instructions, whenexecuted by the circuitry, cause the circuitry to reset the wobblingoperation when a difference between the first auto-focus evaluation andthe second auto-focus evaluation value is greater than a predeterminedthreshold value.
 22. An apparatus comprising: circuitry configured toobtain a plurality of images captured by an imaging device during aperiod of time during which a first wavelength light and a secondwavelength light are alternately irradiated; determine auto-focusevaluation values of at least a first image and a second image eachcaptured by receiving reflected light of the first wavelength light,wherein the first image and the second image are captured with a focuslens of the imaging device in different positions; and determine amovement amount and movement direction of the focus lens by comparingthe auto-focus evaluation values of the at least the first image and thesecond image.
 23. A medical observation method performed by a medicalobservation system including a light emitting device that irradiates asurgical area with first wavelength light and second wavelength light,and circuitry configured to control an imaging device that captures animage of the surgical area, the method comprising: controlling awobbling operation of a focus lens included in the imaging deviceaccording to an emission timing of the first wavelength light and thesecond wavelength light when the surgical area is alternately irradiatedwith the first wavelength light and the second wavelength light.
 24. Animaging apparatus comprising: a light emitting device that irradiates asubject with first wavelength light and second wavelength light; andcircuitry configured to control an imaging device that captures an imageof the subject, wherein in a wobbling operation of a focus lens includedin the imaging device, the circuitry performs control to not move thefocus lens at least during an emission period in which the lightemitting unit emits the first wavelength light.